I have a jug of Roto-Rooter® Pipe Shield® liquid drain cleaner. The directions say I should mix two ounces of Pipe Shield with 32 ounces of water. When I do this, should the total of 34 ounces be applied to each drain or to all seven drains in my house?

You pour a portion of the 34 ounces into each drain once a month. A little bit of Pipe Shield® goes a long way. Depending on how many drains you have in your home, the jug you have could last a year or more.